. >> curtailing the ability of terrorists to come to the united states can be a very effective tool because it essentially eliminates their ability to plan or carry out a tack. >> reporter: more than a decade after the worst terrorist attacks on u.s. soil the u.s. has made progress but is aware that threats remain. >> we dealt them a heavy blow, and we will continue to fight this in yemen, in somalia, in north africa, wherever they go, to make sure they have noplace to hide. >> reporter: leon panetta says al-qaida has been decimated. osama bin laden was killed in a raid by navy seals, and monday the terror group confirmed its second in command was killed by a drone strike in june. >> they're probably not capable of a mass strike in the u.s. but it doesn't mean they aren't capable of lower threshold lower casualty attacks that are frankly more difficult for us to prevent. >> reporter: as for continuing health threats the government announced some 50 types of cancers will be added to the list of illnesses covered by the fund set up to help 9/11 survivors and first responders. >>> d.c. council